ARP Torque Specs for Gen 3 and 4 Engines
ARP Torque Specs – LS Gen 3 / Gen 4 Engines
Quick reference for LS Gen 3 & Gen 4 engines using ARP hardware and ARP Ultra-Torque fastener lubricant.
These values are typical for common ARP kits on LS engines (4.8 / 5.3 / 5.7 / 6.0 / 6.2, non-LS7/LS9). Always verify the exact torque with the instruction sheet supplied with your specific ARP kit.
1. Cylinder Heads – ARP Head Studs
Typical for common ARP LS head stud kits with 11 mm studs and 8 mm outer-row fasteners. Torque in three steps using ARP Ultra-Torque, following the factory LS head torque sequence.
| Fastener | Torque Specification |
|---|---|
| 11 mm head stud nuts (positions 1–10, main rows) | Step 1: 25 ft-lbs → Step 2: 50 ft-lbs → Step 3: 80 ft-lbs |
| 8 mm upper / outer row nuts (positions 11–15) | Torque to 28 ft-lbs |
Some kits and materials (8740 vs ARP2000 vs L19) may specify different final torque values. Always confirm with the ARP instructions for the exact part number you are using.
2. Main Studs – ARP Main Stud Kit
Typical for ARP main stud kits on OEM LS Gen 3/4 blocks with side bolts. Torque in three equal steps (e.g., 20 → 40 → 60 ft-lbs) following the OEM main cap torque sequence.
| Fastener | Torque Specification |
|---|---|
| Inner main studs (long) | 60 ft-lbs (with ARP Ultra-Torque) |
| Outer main studs (short) | 50 ft-lbs (with ARP Ultra-Torque) |
| M8 side bolts | 20 ft-lbs (with ARP Ultra-Torque; use sealant where they enter water jackets) |
| Windage tray nuts (on main studs) | 28 ft-lbs |
3. Connecting Rod Bolts – ARP Rod Bolt Upgrades
Typical for ARP 7/16" rod bolts (ARP2000 or similar) used in LS powdered-metal rod upgrades. Bolt stretch is the primary spec – torque values are a guide.
| Fastener | Torque Specification | Notes |
|---|---|---|
| 7/16" ARP rod bolts (ARP2000, typical LS kit) | ~80 ft-lbs (with ARP Ultra-Torque) | Set to ARP-specified stretch (often ~0.0065–0.0070 in). Use torque only as a reference. |
4. Cam Thrust Plate & Camshaft Sprocket / Gear
Cam Thrust Plate (Cam Retainer)
Use the correct plate and bolt kit for your application. Newer style plates may use countersunk Torx bolts with lower torque.
| Component | Fastener Type | Torque Specification |
|---|---|---|
| Cam thrust plate – 8 mm bolts (typical ARP plate/bolt kit) | ARP 8 mm bolts with ARP Ultra-Torque | ~24–25 ft-lbs |
| Cam thrust plate – countersunk Torx bolts (OEM-style) | Factory-style countersunk bolts | 11 ft-lbs (dry or light oil, per plate/bolt manufacturer) |
Camshaft Sprocket / Cam Gear Bolt
| Component | Application | Torque Specification |
|---|---|---|
| Camshaft sprocket bolts – 3-bolt cam gear | ARP or stock-style 3-bolt LS cam gear | ~25–26 ft-lbs (follow ARP or cam/gear manufacturer instructions) |
| Camshaft sprocket bolt – single-bolt cam (Gen 4 style) | OE torque-to-yield cam bolt | 55 ft-lbs + 50° (replace TTY bolt; follow GM procedure) |
5. Harmonic Balancer (Crank Damper) Bolt – ARP
Typical for ARP LS harmonic balancer bolt kits. Make sure the balancer is fully seated on the crank snout with an installer tool before final torque.
| Fastener | Torque Specification |
|---|---|
| ARP LS harmonic balancer bolt | 235 ft-lbs (with ARP Ultra-Torque) |
6. Flexplate / Flywheel Bolts – ARP
ARP publishes specific torque values for each flexplate/flywheel bolt kit based on bolt material and size. Always use the torque value listed on the instruction sheet supplied with your kit.
| Fastener | Torque Specification | Notes |
|---|---|---|
| ARP LS flexplate / flywheel bolts | Per ARP instruction sheet for your kit | Use ARP Ultra-Torque on threads and under heads. Follow factory star-pattern tightening sequence. |
7. Header / Exhaust Manifold Bolts – ARP Stainless
Typical for ARP stainless LS header bolts using ARP Ultra-Torque or anti-seize on stainless threads.
| Fastener | Torque Specification |
|---|---|
| ARP stainless LS header / exhaust manifold bolts | ~18 ft-lbs |
8. General ARP Fastener Notes
- All values above assume ARP Ultra-Torque Fastener Assembly Lubricant on threads and under the bolt head/washers, unless noted otherwise.
- Torque specs can change between kits, materials (8740 vs ARP2000 vs L19, etc.), and bolt diameters. Always verify the numbers on the ARP instruction sheet for your exact part number.
- For connecting rod bolts, bolt stretch is the primary specification. Use a stretch gauge when possible.
- Follow the factory GM torque sequence for heads and mains while using these ARP values.
- Replace all torque-to-yield (TTY) bolts (factory head, rod, main, cam, and crank bolts where applicable). Do not reuse TTY fasteners.
This page is provided as a convenience reference by Cantrell Customs Performance Engines. Builder is responsible for confirming all torque values with the current ARP documentation and component manufacturers.